Septic tank is rectangular in plan and constructed with brick masonry over a concrete foundation. The length of the tank is usually 3 times the width. R.C.C cover with manhole is provided at the top of the tank.
How does a Septic Tank work?
Septic tank is just like a plain sedimentation tank. The sludge digestion and the sedimentation takes place in the same chamber of this tank. The biochemical reaction takes place by the anaerobic bacteria.
During the detention period, sewage is purified and the effluent is taken to soak pits for disposal. It can remove about 90% of B.O.D and about 80% of suspended solids.
Where a Septic Tank is Suitable?
In order to provide the satisfactory disposal of sewage received or obtained from isolated buildings, small institutions, hotels, and camps, etc. septic tanks may be adopted.
They are suitable for isolated or undeveloped areas where municipal sewers are not laid.